Answer

Tick "Automatically lock my computer when the camera detects that no one is using the computer.

Ensure that you can see a "Green circle" at the camera image, if there is no "Green Circle" at the camera image area, do tilt the screen till you can see yourself in the camera image area. Once you can see yourself, press optimize detection then you should be able to see a "Green circle" around your face.

Set the timeout timers and once its done then press Close to save the settings